1. Field of the Invention
The present invention relates generally to optoelectronic microelectronic fabrications. More particularly, the present invention relates to methods for fabricating optoelectronic microelectronic fabrications with attenuated bond pad corrosion.
2. Description of the Related Art
Microelectronic fabrications are formed microelectronic substrates over which are formed patterned microelectronic conductor layers which are separated by microelectronic dielectric layers.
Known within the art of microelectronic fabrication are purely electronic microelectronic fabrications whose operation is based solely upon electrical signal storage and processing characteristics of purely electronic microelectronic devices and microelectronic circuits formed upon a microelectronic substrate. Examples of such purely electronic microelectronic fabrications typically include, but are not limited to, semiconductor integrated circuit microelectronic fabrications and ceramic substrate microelectronic fabrications. Similarly, also known within the art of microelectronic fabrication are microelectronic fabrications whose operation is based upon a codependent transduction, storage and/or processing of optical and electrical signals while employing optoelectronic microelectronic devices formed upon a microelectronic substrate. Examples of such optoelectronic microelectronic fabrications typically include, but are not limited to: (1) solar cell optoelectronic microelectronic fabrications; and (2) image array optoelectronic microelectronic fabrications such as but not limited to: (a) sensor image array optoelectronic microelectronic fabrications; and (b) display image array optoelectronic microelectronic fabrications.
Common to all microelectronic fabrications, whether purely electronic microelectronic fabrications or optoelectronic microelectronic fabrications, is the use of bond pads as a means for connecting and interconnecting the microelectronic fabrications into useful microelectronic products.
While the use of bond pads for connecting and interconnecting microelectronic fabrications into useful microelectronic products is quite common in the art of microelectronic fabrication, the use of bond pads when connecting and interconnecting microelectronic fabrications into useful products is not entirely without problems in the art of microelectronic fabrication.
In that regard, incident to their exposure to various microelectronic fabrication processes, bond pads are often corroded, eroded, stained or otherwise degraded when fabricating microelectronic fabrications. Although various mechanisms may provide such corroded, eroded, stained or otherwise degraded bond pads, within the context of the present invention the terminology xe2x80x9ccorrosionxe2x80x9d or xe2x80x9ccorrodedxe2x80x9d is intended to include physical and/or electrical performance degradation of a bond pad formed within a microelectronic fabrication, irrespective of the actual mechanism through which such physical or electrical performance degradation actually occurs. Corroded bond pads are undesirable in the art of microelectronic fabrication since it is often difficult to form fully functional or reliable electrical connections to corroded bond pads.
It is thus towards the goal of providing methods and materials for forming within microelectronic fabrications bond pads with attenuated corrosion that the present invention is most generally directed. More particularly, it is also towards the goal of providing methods and materials for forming within optoelectronic microelectronic fabrication bond pads with attenuated corrosion that the present invention is more specifically directed.
Various methods and materials have been disclosed in the art of microelectronic fabrication for forming bond pads with desirable properties.
For example, Thomas, in U.S. Pat. No. 4,491,530, discloses a phenol free and chlorinated hydrocarbon free photoresist stripper composition which may be employed for stripping photoresist layers from microelectronic fabrications while avoiding staining of bond pads which are exposed to the photoresist stripper composition. In conjunction with the absence of phenol and the chlorinated hydrocarbon, the photoresist stripper composition comprises: (1) a surfactant alkylarylsulfonic acid having from twelve to twenty carbon atoms; (2) a hydrotrophic aromatic sulfonic acid having from six to nine carbon atoms; (3) an aromatic hydrocarbon solvent with a boiling point above 150 degrees centigrade; and (4) a substantially water soluble sulfone material.
In addition, Langley, in U.S. Pat. No. 5,376,235, discloses a method for attenuating corrosion of a patterned conductor layer, such as but not limited to a bond pad, within a microelectronic fabrication. The method provides for rinsing the patterned conductor layer with a chromium free dilute phosphoric acid solution in order to remove chlorine contaminants, fluorine contaminants and residual oxide contaminants which would otherwise facilitate corrosion of the patterned conductor layer.
Further, Jones et al., in U.S. Pat. No. 5,380,401, similarly also discloses a method for removing from a bond pad fluorine contaminants and residual oxide contaminants which would otherwise provide the bond pad with an undesirably high contact resistance. The method is a reactive ion etch (RIE) plasma etch method which employs an etchant gas composition comprising argon and carbon dioxide for cleaning from the bond pad the fluorine contaminants and the residual oxide contaminants.
Still further, Sutherland et al., in U.S. Pat. No. 5,461,008, discloses a method for attenuating corrosion of a bond pad within a semiconductor integrated circuit microelectronic fabrication die incident to dicing a semiconductor substrate to form the semiconductor integrated circuit microelectronic fabrication die. The method provides for incorporating into an aqueous coolant medium employed for cooling a dicing saw blade employed for dicing the semiconductor substrate an organic acid at a concentration which provides the aqueous coolant medium with a pH of less than about 5.5. At such pH corrosive silicon particles formed incident to dicing the semiconductor substrate are less adherent to the bond pad.
Finally, Polak et al., in U.S. Pat. No. 5,686,162, discloses a method for attenuating corrosion of electrical components formed within a microelectronic fabrication, such as corrosion of a bond pad formed within the microelectronic fabrication, when encapsulating the microelectronic fabrication with an organic polymer encapsulant material. The method provides for incorporating into the organic polymer encapsulant material a buffer material which neutralizes the effect of a corrosive material which would otherwise corrode the electrical components.
Desirable in the art of microelectronic fabrication are additional methods and materials which may be employed for attenuating corrosion of a bond pad formed within a microelectronic fabrication. More particularly desirable in the art of optoelectronic microelectronic fabrication are additional methods and materials which may be employed for attenuating corrosion of a bond pad formed within an optoelectronic microelectronic fabrication.
It is towards the foregoing objects that the present invention is both generally and more specifically directed.
A first object of the invention is to provide a method for attenuating corrosion of a bond pad formed within the microelectronic fabrication.
A second object of the present invention is to provide a method in accord with the first object of the present invention, where the microelectronic fabrication is an optoelectronic microelectronic fabrication.
A third object of the present invention is to provide a method in accord with the first object of the present invention and the second object of the present invention, where the method is readily commercially implemented.
In accord with the objects of the present invention, there is provided by the present invention a method for fabricating a microelectronic fabrication. To practice the method the method of the present invention, there is first provided a substrate employed within an optoelectronic microelectronic fabrication. Within the present invention, the substrate comprises an optoelectronic device electrically connected with a bond pad formed over the substrate. Finally, when fabricating the substrate to form the optoelectronic microelectronic fabrication, the substrate is processed in the absence of radiation which is optoelectronically transducable by the optoelectronic device, in order to attenuate corrosion of the bond pad.
The present invention provides a method for attenuating corrosion of a bond pad formed within a microelectronic fabrication, where the microelectronic fabrication is an optoelectronic microelectronic fabrication. The present invention realizes the foregoing object when forming an optoelectronic microelectronic fabrication from a substrate comprising an optoelectronic device electrically connected with a bond pad formed over the substrate, by processing the substrate in the absence of radiation which is optoelectronically transducable by the optoelectronic device, in order to attenuate corrosion of the bond pad. Thus, by processing the substrate in the absence of radiation which is optoelectronically transducable by the optoelectronic device, there is attenuated charge formation at the bond pad. Such charge formation would otherwise contribute to corrosion of the bond pad.
The method of the present invention is readily commercially implemented. The present invention employs an optoelectronic microelectronic fabrication apparatus modification and process control which are readily implemented and adapted to the art of optoelectronic microelectronic fabrication. Since the present invention is predicated at least in part upon the recognition of a mechanism through which bond pad corrosion may occur and may be attenuated, rather than predicated upon the existence of methods and materials, the method of the present invention is readily commercially implemented.